Some people can't see the upside-down plates. This one might work for them - it's the same uncropped image rotated ninety degrees both ways.

People are used to illumination coming from above - not from below; so when the scene is illuminated from below, one's brain is inclined to flip the image inside-out to make it better match with the 'usual' illumination.

The effect isn't so strong on my desktop monitor, but when I've seen this pic on my phone, it straight-up looks like a full-color photo unless I zoom way the fuck in. It's especially noticeable in the people's skins, I don't see gray at all, I see a for real human-style flesh tone.

First time I saw it was on a smaller screen, and although I could see the grid lines, I still believed the photo underneath was a normal colour one - until I read the spoiler and checked.

Of course, the colour receptors in our retinas are much more spaced apart than the non-colour ones, and there are very few colour receptors away from the centre of our field of view - so our brains are always dealing with high resolution monochrome images with a much lower resolution colour overlay - this image just helps reveal that in a somewhat surprising way.

If it's not working for you, try squinting a bit, or standing further away from the screen.